Catálogo de publicaciones - revistas

<jats:title>Little things matter</jats:title> <jats:p> Particulate air pollution 2.5 micrometers or smaller in size (PM2.5) is a major cause of human mortality, and controlling its production is a health policy priority. Nitrogen oxides are an important precursor of PM2.5 and have been a focus of pollution control programs. However, Gu <jats:italic>et al</jats:italic> . now show that abating ammonia emissions is also an important component of PM2.5 reduction, and the societal benefits of abatement greatly outweigh the costs (see the Perspective by Erisman). Reducing ammonia emissions thus would be a cost-effective complement to nitrogen oxides and sulfur dioxide controls. —HJS </jats:p>

<jats:title>How to quantify local axonal orientations</jats:title> <jats:p>Mapping the axonal trajectories of the brain’s white matter at cellular resolution is a long-standing goal of neuroscience. However, existing methods for mapping the axons are either limited to animal studies or require highly specialized equipment for data acquisition and processing. Nissl staining identifies cell nuclei and has been used extensively to investigate parcellations of the cortical gray matter, but the white matter has largely been neglected with this technique. Schurr and Mezer now show that Nissl staining, together with structure tensor analysis, can be used to study white matter architecture and the organization of the glial cell framework around axons over the whole brain. This technique greatly advances our knowledge regarding the organization of glial cells and the fine-grained organization of axonal projections in the brain. —PRS</jats:p>

<jats:title>Colorful clones in the blood</jats:title> <jats:p> Stem cells in regenerating tissues such as the blood can acquire mutations that enable a growth advantage, increasing the chance of developing cancer. It is unclear how such diverse mutations promote clonal fitness. Avagyan <jats:italic>et al</jats:italic> . generated a platform in zebrafish to label clones with unique hues while inducing mutations in genes implicated in human blood disorders. Mutations in some genes caused clones to expand over time, resulting in clonal dominance. Progenitors in the dominant clone expressed anti-inflammatory factors to resist the inflammatory environment produced by their own mature progeny, leading to a self-perpetuating cycle promoting clonal fitness. Targeting these resistance pathways may be used to abate clonal hematopoiesis and prevent its associated pathology. —BAP </jats:p>

<jats:title>Detangling gene-disease connections</jats:title> <jats:p> Many diseases are at least partially due to genetic causes that are not always understood or targetable with specific treatments. To provide insight into the biology of various human diseases as well as potential leads for therapeutic development, Pietzner <jats:italic>et al</jats:italic> . undertook detailed, genome-wide proteogenomic mapping. The authors analyzed thousands of connections between potential disease-associated mutations, specific proteins, and medical conditions, thereby providing a detailed map for use by future researchers. They also supplied some examples in which they applied their approach to medical contexts as varied as connective tissue disorders, gallstones, and COVID-19 infections, sometimes even identifying single genes that play roles in multiple clinical scenarios. —YN </jats:p>

<jats:title>A closer look at centromeres</jats:title> <jats:p> Centromeres are key for anchoring chromosomes to the mitotic spindle, but they have been difficult to sequence because they can contain many repeating DNA elements. These repeats, however, carry regularly spaced, distinctive sequence markers because of sequence heterogeneity between the mostly, but not completely, identical DNA sequence repeats. Such differences aid sequence assembly. Naish <jats:italic>et al</jats:italic> . used ultra-long-read DNA sequencing to establish a reference assembly that resolves all five centromeres in the small mustard plant <jats:italic>Arabidopsis</jats:italic> . Their view into the subtly homogenized world of centromeres reveals retrotransposons that interrupt centromere organization and repressive DNA methylation that excludes centromeres from meiotic crossover repair. Thus, <jats:italic>Arabidopsis</jats:italic> centromeres evolve under the opposing forces of sequence homogenization and retrotransposon disruption. —PJH </jats:p>

<jats:title>Insulation for circuit regulation</jats:title> <jats:p> Lipid-rich myelin, which wraps around and insulates neuronal axons, improves the speed and efficiency of signal propagation. Myelination is not universally applied in the central nervous system, and even axons within the same circuit can vary in the amount of myelination they carry. Bonetto <jats:italic>et al</jats:italic> . reviewed what is known about how such variability can affect computational functions in brain circuits. Myelin plasticity may be one mechanism linking experiential learning to modified brain connections. Whether you are learning to juggle or learning to read, changes in myelination may tune the circuits underlying those skills. —PJH </jats:p>

<jats:title>Common basis for language and tool use</jats:title> <jats:p> Tool use and language are hallmarks of human evolution. Because of the similarity between the motor processes for tool use and those supporting language, it has been hypothesized that syntax and tool use may share brain resources. Using functional magnetic resonance imaging and multivariate pattern analysis, Thibault <jats:italic>et al</jats:italic> . found that small portions of the basal ganglia in the human brain act as common neural substrates for both tool use and syntax in language. In a behavioral experiment, they showed that learning a novel task that involves the use of a tool also improves performance in a complex language task. These results further support the hypothesis of a coevolution of tool use and language. —PRS </jats:p>

<jats:p>It has been a rough couple of weeks for scientific public relations regarding COVID-19. Missteps by researchers and funding agencies around the origins of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have provided fodder for conspiracy theorists, and caveats about the children’s vaccine have provided more ammo for anti-vaxxers. None of these miscues say anything substantive about the science and the conclusion that the virus is almost certainly of zoonotic origin and that the vaccine is safe for children. But clumsy behavior is more eye-catching than the details of research, especially when scientists are so often held to unrealistic standards, expected to be both experts in their fields and skilled communicators.</jats:p>

<jats:p>As alarm about climate change and calls for action intensify, solar geoengineering (SG) is seeing increased attention and controversy. Views on whether it should or will ever be used diverge, but the evidentiary basis for these views is thin. On such a high-stakes, knowledge-limited issue, one might expect strong support for research, but even research has met opposition. Opponents’ objections are grounded in valid concerns but impossible to fully address, as they are framed in ways that make rejecting research an axiom, not a conclusion based on evidence.</jats:p>